For electronic equipment, small volume is a desirable attribute. Logic circuits have achieved small volume by being embodied in integrated circuits. However, achieving small volume for lumped elements such as resistors, capacitors, and inductors has proved more difficult, particularly for capacitors and inductors used at lower frequencies and higher currents. For many applications, capacitors of high capacitance values, such as those used for power supply and bypass filtering or low frequency coupling, are provided in the form of surface mounted packages.
More recently, a variety of techniques for fabricating a very thin crystallized dielectric oxide layer useful for embedding within a multi-layer circuit board have been publicized. These techniques provide capacitive densities far exceeding previous methods. Methods of providing connections to and through these layers have been developed, but further improvement in this aspect is desirable, to lower direct costs and improve yields.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.